Stair construction and unit block therefor



Sept. 21, 1937. A. LEE

STAIR CONSTRUCTION AND UNIT BLOCK THEREFOR Filed July 19, 1954 Patented Sept. 21, 1937 UNiTED fiTA'I'ES ranges STAIR CONSTRUCTION AND UNIT BLOCK THEREFOR Arthur Lee, Wilmette, Ill.

Application July 19, 1934, Serial No. 735,918

2 Claims.

This invention relates to improvements in stair constructions and refers specifically to stairs constructed of a plurality of preformed blocks of L-section, the construction being characterized in that the stairs may be used prior to the complete setting of the concrete which latter ultimately supports the stairs.

The utility, objects and advantages of my in- Vention will be apparent from the accompanying drawing and following detail description.

In the drawing, Fig. 1 is a side elevational View of a portion of a stair constructed in accordance with the concept of my invention.

Fig. 2 is a fragmentary perspective view of the stair.

Fig. 3 stair.

Fig. 4 is a sectional View of the stair block.

Fig. 5 is a bottom plan view of the unit shown in Fig. 4.

Referring in detail to the drawing, I indicates a unit block, a plurality of which when disposed in proper relationship with respect to one another comprise the treads and risers of the stair 2. The blocks I may be L-shaped in longitudinal section, the arms of the L comprising treads 3 and risers 4. The height of the risers I and the length of the treads 3, of course, will depend upon the pitch of the stairs. The units I may, if desired, be provided with a nose 5 or the juncture of the riser and tread may be square.

In constructing the stair 2, a form Ii of wood may be built at an angle corresponding to the pitch of the stair. Metal reinforcing rods I may be disposed parallel to form 6, one or more of such rods being provided for each longitudinal course of units I. A plurality of transverse reinforcing rods 8 may be tied to rods I, one rod 8 being provided for each step.

The rear edge of each of the treads 3 may be provided with a recess 9, the inner defining edge of said recess being beveled as shown at I 0 in Figs. 4 and 5. In addition, the face of each of the treads 3 may be provided with a transverse groove I I which may intersect with recess 9.

A plurality of unit blocks I may be positioned in side abutting relationship, the lower rear corner of the treads thereof being adapted to rest and be supported upon the pitched form 6. The blocks may be so disposed that rods I pass through recesses 9 and rods 8 are positioned in grooves I I. Blocks I are so positioned that the risers of the blocks, comprising the tier or step above, rest upon the treads of the blocks com- 55 prising the adjacent lower tier or step. In this is a top plan view of a portion of the manner the stairs 2 when initially assembled are self supporting, the forward edges thereof or risers being supported upon the adjacent lower treads and the rear portions of the blocks being supported by form 6. 5

Metal hooks I2 may be embedded in the bottom of each of the risers l, said hooks extending rearwardly and being adapted to engage one of the defining edges of recess 9 provided in block I immediately below the block in question. In this manner the blocks in their assembled state, prior to and during the pouring of the concrete foundation, hereinafter described, are prevented from being relatively displaced.

After the blocks have been assembled in stair form, as hereinbefore described, concrete I3 may be poured beneath the blocks, said concrete surrounding the reinforcing rods I and 8 and providing a strong sub-structure for the stairs 2. Rods I and 8 are preferably so disposed with respect to blocks I that a considerable thickness of concrete surrounds said rods.

After the concrete has set, forms 6 may be removed. However, before the pouring of the concrete and during the setting of the concrete after pouring and prior to the removal of forms 5, the stair may be used, inasmuch as the selfsupporting character of the assembly is such as to withstand ordinary loads without collapsing or injuriously affecting the setting concrete. 30

It is to be understood, of course, that the width of the stairs 2 may comprise the width of one or more blocks I, and the thickness and material of which blocks I are constructed may be correlated with respect to the loads to which the stairs may be subjected. Rods 8, if desired, may extend beyond the confines of the stairs and may be embedded in side walls I4. It is to be understood further, that the entire space between blocks I and forms 6 need not be filled with concrete so long as an appreciable thickness of concrete surrounds rods I and 8. For usual stair loads a thickness of 2 inches of concrete taken in all directions from rods I and 8 will suflice, but a greater or lesser thickness may be found desirable to meet special loading conditions.

In the usual stair constructions the walls adjacent the stairs must be constructed first and the stairs subsequently erected. In my stair construction the supporting rods 8 may be set in 50 place when the wall is being built and the stairs may be erected apace with the erection of the walls.

Blocks I may be constructed of any material which has sufiicient strength to withstand the loads the stairs are designed for, such as, concrete, in any of its forms, clay, stone or the like.

I claim as my invention:

1. A stair construction comprising in combination, a plurality of preformed blocks disposed in tiers, each of said blocks having risers and treads, the risers of one tier resting on the treads of the adjacent lower tier, the rear portions of the treads being provided with recesses opening to the rear edge thereof and the faces of the treads being provided with transverse grooves, reinforcing rods disposed in said recesses and reinforcing rods disposed in said grooves, and concrete surrounding said reinforcing rods.

ARTHUR LEE. 

